The measurement of ocular blood flow is essential to improve the understanding of several diseases afflicting the eye, including glaucoma. One of the hypotheses for the cause of glaucoma is that the optic nerve tissue is damaged by insufficient blood flow because of a deficiency in the tissue's ability to regulate its own blood supply in response to increased intraocular pressure. A clinically useful bloodflow measurement tool is necessary to further examine this hypothesis. In the proposed research, two recently developed technologies will be combined in order to form one powerful, clinical tool for the measurement of blood flow in the optic nerve head. A confocal laser Doppler flowmeter will be coupled to a confocal scanning laser ophthalmoscope. This combination would allow for non-invasive, noncontact blood flow measurements in the living eye through the undilated pupil. The confocal detection method employed in this instrument would allow for depth-resolved blood flow measurements in the optic nerve head. PROPOSED COMMERCIAL APPLICATION: Potentially, this research will lead to the development of a non-invasive, clinical instrument for the depth- resolved measurement of optic nerve blood flow and optic nerve topography through the undilated pupil.